Polishing machine for workpieces

ABSTRACT

A polishing machine is provided which has an oscillatable frame supporting at least one hollow drum adapted for receiving the workpieces to be treated, each drum being rotatably supported from a pair of discs which in turn are supported from the frame for rotation about an axis which is perpendicular to the axis of rotation of the frame and is in the same plane therewith. The drum undergoes movement influenced by three independent rotations which are respectively controllable.

United States Patent inventor Ernst Ileiberger Reichenbach Rechberg, Germany Appl. No. 785,987 Filed Dec. 23, 1968 Patented May 25, 1971 Assignee Gualdipex S.A.

Zurich, Switzerland Priority Dec. 22, 1967 Germany P 16 52 065.3

POLISHING MACHINE FOR WORKPIECES 20 Claims, 8 Drawing Figs.

US. Cl 51/164, 241/ 1 77 Int. Cl 1324b 31/02 Field of Search... 51/164;

[56] References Cited UNITED STATES PATENTS 2,726,069 12/ l 955 Thorstensson-Rydberg. 259/81 3,139,708 7/1964 Oetiker 51/164 3,341,979 9/1967 Davidson et a1. 51/164 Primary ExaminerTravis S. McGehee Attorney-Waters, Roditi, Schwartz & Nissen 0 ABSTRACT: A polishing machine is provided which has an oscillatable frame supporting at least one hollow drum adapted for receiving the workpieces to be treated, each drum being rotatably supported from a pair of discs which in turn are supported from the frame for rotation about an axis which is perpendicular to the axis of rotation of the frame and is in the same plane therewith. The drum undergoes movement influenced by three independent rotations which are respectively controllable.

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PATENTEU mes i9?! SHEET R [If S rouse MACHTNE roa WOW t. IECES BRIEF SUMMARY OF THE INVENTION The invention relates to a tumbling or polishing machine for surface processing or treatment of workpieces resulting from manufacturing processes, especially when the workpieces are made of metal. More particularly, the invention is concerned with smoothing such workpieces and also breaking or rounding off sharp edges on the workpieces.

In previously known tumbling machines, the workpieces are introduced together with abrading or polishing agents into a drum rotating about a fixed horizontal axis. During operation, the coaction of frictional and gravitational forces produces a certain relative movement of the contents in the drum.

It has been attempted to improve this relative movement of the contents of the drum by mounting several drums on a rotation disc or plate, the axes of rotation of said drums being arranged parallel to the fixed axis of rotation of the disc or plate. The effect of mounting the drums on a rotating disc or plate is that the centrifugal forces exerted on the contents of the drums, because of the two rotational movements, are added or subtracted according to the particular configuration. Such machines are constructed both with vertical rotors and drum axes and with horizontal axes. Variations in the design of vertical tumbling machines consist in the drums being mounted either at only one end or at both ends. Difficulties arise with drums mounted only at one end, since above all, with relatively large machines, a moment of considerable magnitude acts on the drum mounting because of the centrifugal forces which occur. As a consequence, the centrifugal force component, which per se is desirable to create relative movement of the contents, restricts or limits the applicability of this mode of construction and above all limits the sizes of these machines.

It is true that this problem does not arise with drums supported at both ends, but it is necessary instead to accept other disadvantages; for example, in known constructions, for filling and emptying the drums, it is necessary to remove one of the bearing holders in order to be able to open the covers of the drums.

The known tumbling machines having vertical rotors and drum axes have the additional deficiency that the drums have to be fitted with a lifting tool for emptying purposes and tipped outside the machine. And, for rinsing and polishing the workpieces, the drums have to be transferred to a second installation. In addition, if the workpieces are of higher specific gravity than the abrading or polishing agents, they may become separated in the drum because of their higher specific gravity and may be deposited on the bottom.

In another known tumbling machine having a horizontal rotor or drum axes, the drums are mounted at both ends on or in two rotor discs. An opening which can be tightly closed with a lid or cover is disposed in the sidewall of the drums for charging and emptying the latter. However, since the wall surfaces are directly loaded to a particular degree by the material to be tumbled, these covers must be made very stable and be reliably connected to the drum wall. The opening and closing of the drums is comparatively complicated and time consuming as is the filling and removal due to the fixed horizontal axes of the drums. An additional disadvantage of this known tumbling machine is that the covers of the drums cannot be closed without a gap, so that small components can be trapped in the gaps and be bent. A further disadvantage is that the usual flushing of the drum can only be carried out by hand with the machine stationary and with the cover open.

An object of the present invention is to avoid the disadvantages and defects of the known tumbling and polishing machines and to provide a machine which is improved as regards efficiency, the time required for the treatment of the workpieces and the simplicity and economic working procedure as regards the use and operating of the machine.

According to this invention there is provided a machine of the kind specified having one or more drums supported for rotation about respective axes, the drums being mounted on two spaced discs or plates which are rotatably mounted in a frame, which in turn is pivotable about an axis which is inclined with respect to the axis of rotation of the discs. By this means, a gimbal suspension of each drum is obtained, whereby the movement of the workpieces inside the drum during operation (in which firstly the drum and the rotor discs are rotated and secondly the frame is tilted backwards and for wards about its axis in a range of about 180) is influenced in a particularly advantageous manner, so that the output capacity of such a machine may be considerably greater than that of the known machines, both as regards the quality of the processing and also as regards the time required for the latter. In particular, the oscillation of the frame causes a more thorough andfaster flushing operation. The axis of rotation of the rotor discs is preferably at right angles to the axis of rotation of the frame and may be in the same plane therewith. Two drums in axially parallel relation may be mounted on the rotor discs or plates on opposite sides of the axis of rotation of the discs or plates. The drums may be cylindrical and may be equispaced from the axis of rotation of the rotor discs and diametrically opposite from one another with respect to'said axis of rotation.

In order to drive the various movable parts of the machine according to the invention, it is advantageous to provide individual drives, for example, hydraulic motors; and these are particularly used also for the purpose of separately controlling these parts. The drive means for the frame is adapted to cause the frame to carry out a vibratory or oscillatory movement. These separate drives can be arranged in the immediate vicinity of the parts themselves and be coupled to the latter. However, it is also possible for the separate parts to be driven by way .of belts or gears, so that the driving motors are arranged externally of the movable parts on the frame.

Furthermore, according to the invention each drum of the machine may be mounted in a bearing in an aperture in one of the rotor discs, one end of the drum being open and disposed on the outer side of said disc, while the other end of the drum is mounted on another rotor disc spaced from the first disc. This construction enables rapid charging and emptying of the drums and flushing thereof with a liquid.

Each drum is provided with a cover with a quick-closure device and in addition with a union for connection with a liquid conduit, through which flushing liquid or treatment liquid can be introduced into the interior of each drum. The introduction of this liquid can be effected through a hollow shaft supporting the discs and connected to the drum. The discharge of the liquid is effected by way of outlet openings in a closable liquid outlet in the cover, in which a sieve is arranged. The machine according to the invention is preferably constructed so that the ratio between the diameter of the drum and the diameter of the circular path which is described by the axis of the drum during its movement amounts to approximately l:2.3. The machine is also constructed so that the speed of rotation of each drum is twice as fast as that of the rotor discs carrying it.

According to another aspect of this invention there is provided a method of tumbling or polishing workpieces using a machine in accordance with the invention. The speed of rotation of each drum is twice that of the rotor plates carrying the drum.

In the construction of the prior known tumbling and polishing machines, it was assumed that it would be particularly desirable if, the operating centrifugal forces which act on the workpieces in the drums due to the rotation of the rotor disc were substantially greater than those resulting from the rotational movement of the drums themselves. Thus, the ratio between the drum speed and the rotor disc speed has formerly been about 0.4-0.5:1. Nevertheless, the assumptions and opinions in this respect need to be revised on the basis of the knowledge which has been acquired from numerous tests of a machine according to the invention. It is possible to establish that the treatment or processing time for the workpieces can It is obvious that optimum operating conditions should be empirically established for each type of workpiece and then systematically adhered to. For this reason, the speeds of rotation of the individual movable parts of the machine are preferably made adjustable and are in fact adapted to be independently regulable in order to achieve the best possible working capacity.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a tumbling and polishing machine with two drums, according to the invention, in simplified form with the drive means omitted;

FIG. 2 is an elevational cross section through the machine with only one drum being shown;

FIG. 3 is a side elevation view of the machine in the filling position;

FIG. 4 is a side elevation corresponding to FIG. 3, with the drums in the emptying position;

FIG. 5 is a front elevational view, partly broken away and in section, of a machine similar to that in FIG. 1 but with four drums and the drive means illustrated;

FIG. 6 is a plan view, partly in section, of the machine of FIG. 5;

FIG. 7 is a side elevation view partly in section of a machine similar to that of FIG. 5 but with a modified drive means for the drum; and

FIG. 8 is a cross-sectional view of a detail showing the end portion of a drum and the closure therefor.

DETAILED DESCRIPTION The basic structure of the tumbling and polishing machine will be seen from FIG. 1. This machine comprises a support 11 with two bearings 12, in which are mounted shafts 13 of a frame 14, which is mounted so as to be pivotable about a horizontal axis X-X. Mounted in this frame 14 is a shaft l5, rotatable about axis Y-Y which is disposed in the same plane as axis X-X and perpendicular thereto. Consequently, there is provided a gimbal suspension for two tumbling and polishing drums 18 mounted on rotor discs 16 and 17. The rotor disc 16 is secured on shaft and carries two bearings 19 (one of which is shown in FIG. 2). In each bearing 19 there is rotatably mounted a drum shaft 20 secured to base wall 180 of a respective drum 18. A driving force for rotating the drums is operative on shafts 20. At their other ends, the drums 18 are supported by means of the engagement of drum wall 18b in a roller bearing 21 in an aperture in the rotor plate 17, the drum wall 18b projecting outwardly somewhat beyond the plate 17. On this outer side of the plate 17, each drum 18 is adapted to be closed by a cover 22, which is provided with a closure device which is quickly released and secured so that the cover can be both quickly and easily released and removed and subsequently fitted and secured in place. Attached to the cover is a connecting union 23 for the connection of a liquid supply 24.

In order to fill or empty the drums, they are inclined with their charging or emptying opening 18c extending obliquely upwards and downwards, respectively, by being tilted about the axis X-X or the frame 14, as can be seen from FIGS. 3 and 4.

In one particularly advantageous constructional form of the machine, the radius of each of the drums 18 is half as large as the spacing between the drum axes Z and the axis Y of the rotor discs or plates 16,17; furthermore, the machine and its drive means are so constructed that the speed of rotation of the drums 18 is twice as fast as that of the rotor plates 16,17.

The driving of the moving parts of the machine according to the invention is advantageously effected by separate driving motors, which may be hydraulic or electrical.

As shown in FIGS. 5 and 6 two motors 25,26 respectively drive the rotor shaft 15, and the drums 18 independently of one another. The motors 25,26 are mounted on a suspension 14a of the pivotable frame 14. The motors 25,26 are connected via cables 27 to a supply source. Thus, if motors 25,26

are electrical, the cables 27 are connected to an electrical voltage source for driving the motors. The cables 27 are flexible to follow the swiveling motion of the frame about the axis X-X which is in the range of about If the motors are hydraulic, the cables 27 are in the form of tubing for the supply of pressure fluid to operate the motors.

The motor 25 driving the shaft 15 is drivingly coupled by a transmission belt 28 to a ring 29 mounted on the disc 16 and serving as a belt pulley.

The motor 26 driving drums 18 is drivingly coupled by means of a transmission belt 30 to a belt pulley 31 loosely positioned on the shaft 15. Hub 31a is designed to act as a belt pulley and is coupled to a toothed belt 32 which passes around belt pulleys arranged on the shafts 20 of drums 18 within the ring 29. This construction allows an infinitely variable control of the rotational speed of drums 18 independent of the rotational speed of rotor shaft 15, or rotor discs 16,17 respectively.

FIG. '7 shows a slightly modified construction for the drive of drums 18 wherein each of the shafts 20 of the drums 18 is driven from a respective driving motor 34, preferably a hydraulic motor. However, as in the embodiment according to FIGS. 5 and 6 the driving of the rotor shaft 15 is effected by means of a driving motor on the frame 14 in turn driving the ring 29, mounted on the rotor disc 16 and surrounding the hydraulic motors 34 by means of the belt 28. The supply of the pressure fluid to the hydraulic motors 34, and the drainage therefrom is effected, respectively, by means of flexible tubings 27 through a sleeve 35 provided with two separate ducts 36,37 connected to annular grooves 38,39, said sleeve being loosely positioned on the rotor disc shaft 15 so as to be nonrotatable. Sleeve 35 is surrounded by a rigid rotating housing 40 connected to the disc 16. Tubings 41,42 are connected on the one hand to the hydraulic motors 34 and on the other hand to the housing 49 so as to terminate in the annular grooves 38,39 in the housing 40 and supply the motors 34 with pressure fluid.

In order to insure synchronous running of the drums, they are coupled to each other by a common toothed belt 51, or the like, so that any torque differences of the separate hydraulic motors are compensated.

As many be seen from FIGS. 6 and 7, a hydraulic cylinder 43 is arranged between the frame 114 and the support 11 for the purpose of pivoting the frame 14 about the axis X-X to rock the drums 18. The pivoting movement of the frame 14 about the axis X-X is preferably made 5 to 10 times per minute during the tumbling or polishing action, which results in a particularly favorable mixing of the workpieces contained in the drums 18 with the abrading or polishing agents. Also, the pivoting movement of the frame 14, and the drums 18 therewith, during the rinsing operation has the effect that the workpieces are particularly thoroughly cleaned. Furthermore, the filling and emptying of the drums 18 is promoted by the tilting of the frame 14 about axis X-X and respectively holding the same in positions in which the drum openings are directed upwardly and downwardly. In fact the drums 18 may be emptied automatically under the action of gravity.

As shown in FIGS. 6 and 8, a flushing liquid is supplied to the drums 18 through a tube 44 connected by means of a coupling 45 to the hollow rotor shaft 15 so that said shaft 15 is rotatable with respect to the tube. On the shaft 15 there is mounted a distributor ring 46 connected to the supply tubes 23 which are fastened to the covers 22 for conveying the flushing liquid to drums 18. The connection of the supply tubes 23 with the covers 22 of the drums 18 is also designed to be a revolving turret so that drums 18 may rotate with respect to tubes 23. Socket couplings are arranged in the distributor ring 46 so as to permit removal of the covers 22 with the tubings 23 connected thereto. Between the cover 22 and the drum 18 there are provided two elastic plates 48 (FIG. 8), preferably rubber, having aligned holes 7. Between the plates 48 is a screen 49. The cover 22, has hoies 47' corresponding to holes 47, and the cover 22 may be rotated relative to the rubber plates 48 which are fixed in position and secured to drum 18 by a pin 54. Consequently, the holes 47, 47' may be made to coincide with each other and the flushing liquid discharged from the drum 18, or alternatively, the holes 47, 47' can be staggered so that the drum is sealed. 7

The operation of the tumbling or polishing machine according to the invention with the holes 47, 47 in alignment, i.e. with the drums 18 set for discharge, is particularly advantageous inasmuch as during the working process, water may be continuously supplied by tubes 23 to provide a flushing action. This is considerably simplified by the specific design of the cover 22 since constantly fresh water may be supplied through tubes 23 and the polishing agent as well as the abraded particles of the workpieces may be discharged through aligned holes 47, 47.

In order to enable the cover 22 to be removed or installed quickly, the drum 18 is provided with a snap closure 50 comprised of a bolt lever 52 and a tension hook 53 designed to engage in a groove 55 provided at the edge of cover 22.

lclaim:

l. A polishing machine comprising a frame supported for pivotal movement about an axis of rotation, at least one hollow drum adapted for receiving workpieces to be polished, a pair of spaced discs rotatably supporting said drum, one of said discs having an opening for each drum, bearing means rotatably supporting each drum in its respective opening, each drum extending through its respective opening and having a closed end rotatably supported by the other disc and an open end spaced from said one disc on a side thereof opposite the closed end and means supporting said discs from said frame for rotation about an axis which is inclined to the axis of rotation of said frame.

2. A machine according to claim 2 wherein the axis of rotation of the discs is at right angles to the axis of rotation of the frame.

3. A machine according to claim 1 wherein the axis of rotation of the discs is in the same plane as the axis of rotation of the frame.

4. A machine according to claim 1 wherein two drums in axially parallel relation are mounted on the discs on opposite sides of the axis of rotation of the discs.

5. A machine according to claim 1 comprising a shaft secured to each drum at the closed end thereof and rotatably mounted in said other disc.

6. A machine according to claim 1 comprising first drive means for rotating the drums relative to the discs, second drive means for rotating the discs relative to the frame, and

third drive means for pivotably moving said frame, said first, second and third drive means being independent of one another and individually regulable.

7. A machine according to claim 6 wherein said first and second drive means respectively comprise hydraulic motors.

8. A machine according to claim 6 wherein said third drive means is operable to oscillate the frame.

9. A machine according to claim t5 wherein said second drive means is operable to rotate the discs alternatively in opposite directions.

10. A machine according to claim 1 comprising a cover for said open end of each drum and quick release means for attachment of the cover to the drum.

11. A machine according to claim 10 wherein the cover of each drum includes a connecting union for connection to a conduit for a liquid.

12. A machine accordingto claim 11 wherein said means supporting said discs comprises a hollow rotatable shaft adapted for connection with a supply of liquid and with said union of each drum for the introduction of liquid into the drum.

13. A machine according to claim 12 wherein each said cover includes a closable liquid outlet.

14. A machine according to claim 13 comprising a screen within the closable liquid outlet.

15. A machine according to claim 1 wherein two cylindrical drums are provided, the ratio between the diameter of the drums and the diameter of the circular path described by the axes of the drums when the disc rotate is at least 1 :2.3.

16. A machine according to claim 15 wherein the speed of rotation of each drum is twice that of the discs carrying the drum.

17. A machine according to claim 1 wherein the axis of rotation of the drum is offset from the axis of rotation of the discs.

18. A machine according to claim 17 comprising a drive means for said drum comprising a first drive pulley coaxial with said axis of rotation of the discs, a second pulley coaxial with said drum and drivingly coupled thereto, and an endless belt drivingly connecting the pulleys.

19. A machine according to claim 18 comprising a further drive means coupled to said other disc to drive the same rela-' tive to said frame.

20. A machine according to claim 19 comprising a shaft secured to said drum at the closed end thereof and rotatably mounted in said other disc, said second pulley being rigidly mounted on the latter shaft. 

1. A polishing machine comprising a frame supported for pivotal movement about an axis of rotation, at least one hollow drum adapted for receiving workpieces to be polished, a pair of spaced discs rotatably supporting said drum, one of said discs having an opening for each drum, bearing means rotatably supporting each drum in its respective opening, each drum extending through its respective opening and having a closed end rotatably supported by the other disc and an open end spaced from said one disc on a side thereof opposite the closed end and means supporting said discs from said frame for rotation about an axis which is inclined to the axis of rotation of said frame.
 2. A machine according to claim 2 wherein the axis of rotation of the discs is at right angles to the axis of rotation of the frame.
 3. A machine according to claim 1 wherein the axis of rotation of the discs is in the same plane as the axis of rotation of the frame.
 4. A machine according to claim 1 wherein two drums in axially parallel relation are mounted on the discs on opposite sides of the axis of rotation of the discs.
 5. A machine according to claim 1 comprising a shaft secured to each drum at the closed end thereof and rotatably mounted in said other disc.
 6. A machine according to claim 1 comprising first drive means for rotating the drums relative to the discs, second drive means for rotating the discs relative to the frame, and third drive means for pivotably moving said frame, said first, second and third drive means being independent of one another and individually regulable.
 7. A machine according to claim 6 wherein said first and second drive means respectively comprise hydraulic motors.
 8. A machine according to claim 6 wherein said third drive means is operable to oscillate the frame.
 9. A machine according to claim 6 wherein said second drive means is operable to rotate the discs alternatively in opposite directions.
 10. A machine according to claim 1 comprising a cover for said open end of each drum and quick release means for attachment of the cover to the drum.
 11. A machine according to claim 10 wherein the cover of each drum includes a connecting union for connection to a conduit for a liquid.
 12. A machine according to claim 11 wherein said means supporting said discs comprises a hollow rotatable shaft adapted for connection with a supply of liquid and with said union of each drum for the introduction of liquid into the drum.
 13. A machine according to claim 12 wherein each said cover includes a closable liquid outlet.
 14. A machine according to claim 13 comprising a screen within the closable liquid outlet.
 15. A machine according to claim 1 wherein two cylindrical drums are provided, the ratio between the diameter of the drums and the diameter of the circular path described by the axes of the drums when the disc rotate is at least 1:2.3.
 16. A machine according to claim 15 wherein the speed of rotation of each drum is twice that of the discs carrying the drum.
 17. A machine according to claim 1 wherein the axis of rotation of the drum is offset from the axis of rotation of the discs.
 18. A machine according to claim 17 comprising a drive means for said drum comprising a first drive pulley coaxial with said axis of rotation of the discs, a second pulley coaxial with said drum and drivingly coupled thereto, and an endless belt drivingly connecting the pulleys.
 19. A machine according to claim 18 comprising a further drive means coupled to said other disc to drive the same relative to said frame.
 20. A machine according to claim 19 comprising a shaft secured to said drum at the closed end thereof and rotatably mounted in said other disc, said second pulley being rigidly mounted on the latter shaft. 